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Unformatted text preview: y resulting from one crossover, 150 progeny from the other crossover, but only 15 progeny resulting from the double progeny. March 19, 2012 BIS101001, Spring 2012--Genes and Gene Expression, R.L. Rodriguez 2012 24 Relating RF to Genetic Distance
Genetic Distance. Although there are special circumstances that make crossing over more or less likely along a given stretch of DNA (see interference below), the crossover frequency (or recombination frequency) can be used to approximate genetic distance based on the following assumptions: 1% recombination = 1 crossover/100 postmeiotic events = 1 map unit (In honor of TH Morgan, 1 map unit (m.u.) has been designated 1 centiMorgan or 1 cM) (Remember, 1 crossover produces 2 crossover gametes so recombinant progeny must be added together when calculating % recombination as shown below) In Morgan's 2-factor cross, the genetic distance between the pr and vg loci can be determined by calculating the frequency of recombinant progeny. Total Recombinant Progeny Total Progeny
March 19, 2012 270 + 270 X 100 5849 X...
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This note was uploaded on 03/18/2012 for the course BIS 101 taught by Professor Simonchan during the Winter '08 term at UC Davis.
- Winter '08